As shown in FIG. 2, for a hydraulic excavator 1 serving as a work machine, an upper structure 3 is rotatably provided on a lower structure 2, on this upper structure 3, mounted is an operating unit 5 with a cab 4, and for this operating unit 5, pivotally supported on the upper structure 3 is a boom 6 to be pivoted in the up-and-down direction by a boom cylinder 6c, pivotally supported on a front end of this boom 6 is a stick 7 to be pivoted in the in/out direction by a stick cylinder 7c, and pivotally supported on a front end of this stick 7 is a bucket 8 to be pivoted by a bucket cylinder 8c. 
The boom cylinder 6c and the stick cylinder 7c are controlled by spool-type pilot-operated control valves, and respective pilot-operated control valves for the boom and stick are provided two each so that the operation speed, that is, flow rate, of each cylinder can be sufficiently secured (see Japanese Laid-Open Patent Publication No. 2003-232305 (e.g., Page 5, FIG. 1) for example).
In such a control valve circuit, when a horizontal dragging work is carried out while the front end of the bucket 8 is kept touching the ground, it is necessary to devise so that an interlocking operation between boom up and stick in can be smoothly carried out (see Japanese Laid-Open Patent Publication No. 2000-96629 (e.g., Pages 5-6, FIG. 1), for example).
FIG. 3 shows a valve control unit of a conventional hydraulic control work machine that directly controls the pilot pressure of a pilot-operated spool valve by a remote control valve.
That is, a first boom spool valve 11 is stroke-controlled by a boom-up pilot pressure Pa and a boom-down pilot pressure Pb, and a first stick spool valve 12 is stroke-controlled by a stick-in pilot pressure Pc and a stick-out pilot pressure Pd, while a second boom spool valve 13 for securing a boom-up flow rate is stroke-controlled by the boom-up pilot pressure Pa and the stick-in pilot pressure Pc.
Although the second boom spool valve 13 feeds hydraulic oil to a head side of the boom cylinder 6c, for an interlocking operation with a stick-in motion, it is necessary to suppress the boom-up speed, the stick-in pilot pressure Pc against the boom-up pilot pressure Pa is made to act on the second boom spool valve 13.
The boom-up pilot pressure Pa is a pilot pressure outputted from a remote control valve 14, and the stick-in pilot pressure Pc is a pilot pressure outputted from a remote control valve 15, however, Operation Table Characteristics 16 of these control valves 14 and 15, that is, lever operation angle/pilot pressure characteristics, of these remote control valves are identical.
Thus, in the case of a hydraulic control type, since the operation table characteristics (relationship between the lever operation angle and pilot pressure for spool displacement control) are the same for every motion, control balance of the second boom spool valve 13 is maintained, and an interlocking operation between boom up and stick in can also be smoothly carried out.
Where this is applied to a valve control unit of an electrical control work machine that controls pilot pressures Pa, Pc, and the like by proportional solenoid valves 21 to 24, only when an Operation Table 25 of the proportional solenoid valves 21 and 22 are made identical to an Operation Table 26 of the proportional solenoid valves 23 and 24, the control balance of the second boom spool valve 13 is maintained, and the interlocking motions are smoothly carried out as shown in FIG. 4, however, in this electrical control hydraulic excavator shown in FIG. 4, the Operation Tables 25 and 26 for respective motions can be separately set so as to determine optimal operability in any situation.